Disk drive having a system for protecting the read/write heads

ABSTRACT

An improved disk drive includes an improved operating system, an improved eject system, an improved head retract system and an improved motor loading system. In a preferred embodiment of the operating system it includes a motor, an eject crank, a head crank and an actuator. The output of the motor can be selectively controlled by the actuator to power either the eject crank or the head crank. Powering the head crank, causes the disk drive heads to move, and powering the eject crank causes a disk cartridge to be ejected from the disk drive. The motor loading system may have a disk drive motor having a threaded exterior and a member extending from the exterior to interface with the eject system. Additionally, this motor loading system may include an aperture in the chassis of the disk drive that has a threaded ring running around the circumference of the aperture and a spring extending from the threaded ring. The disk drive motor can be inserted into the aperture in the chassis with the member depressing the spring. The disk drive motor can then be rotated to mate the threads of the disk drive motor with the threaded ring. When rotated, the slotted member releases the spring. The spring prevents rotation of the disk drive motor past a predetermined point and thereby prevents the motor from becoming dislodged from the chassis. When inserted into the disk drive, the motor can be moved between a loaded and an unloaded position.

This application is a divisional of application Ser. No. 08/866,225filed May 30, 1991, U.S. Pat. No. 6,072,666 entitled “An Improved HeadRetraction system For Retracting The Heads Of A Disk Drive.”

FIELD OF THE INVENTION

The present invention relates to disk drives of the type that acceptremovable disk cartridges. More particularly, this invention relates toan improved disk drive that has an improved system for and method ofejecting a disk cartridge from a disk drive, an improved system for andmethod of retracting and holding the read/write heads of a disk drive ina retracted position, an improved system of and method for operating aneject system and a retraction system of a disk drive and an improvedsystem for and method of loading a motor for engaging a hub of a diskcartridge.

BACKGROUND OF THE INVENTION

Disk drives for storing electronic information are found in a widevariety of computer systems, including workstations, personal computers,and laptop and notebook computers. Such disk drives can be stand-aloneunits that are connected to a computer system by a cable, or they can beinternal units that occupy a slot, or bay, in a computer system. Laptopand notebook computers have relatively small bays in which to mountinternal disk drives and other peripheral devices, as compared to themuch larger bays available in most workstation and personal computerhousings. The relatively small size of peripheral bays found in laptopand notebook computers, can place significant constraints on thedesigner of internal disk drives for use in such computers. Techniquesthat address and overcome the problems associated with these sizeconstraints are therefore important.

Disk drives of the type that accept removable disk cartridges havebecome increasingly popular. One disk drive product that has been verysuccessful is the ZIP™ drive designed and manufactured by IomegaCorporation, the assignee of the present invention. ZIP™ drives acceptremovable disk cartridges that contain a flexible magnetic storagemedium upon which information can be written and read. The disk-shapedstorage medium is mounted on a hub that rotates freely within thecartridge. A spindle motor within the ZIP™ drive engages the cartridgehub when the cartridge is inserted into the drive, in order to rotatethe storage medium at relatively high speeds. A shutter on the frontedge of the cartridge is moved to the side during insertion into thedrive, thereby exposing an opening through which the read/write heads ofthe drive move to access the recording surfaces of the rotating storagemedium. The shutter covers the head access opening when the cartridge isoutside of the drive, to prevent dust and other contaminants fromentering the cartridge and settling on the recording surfaces of thestorage medium.

The ZIP™ drive is presently available for workstations and personalcomputers in both stand-alone and internal configurations. In order toprovide a version of the ZIP™ drive for use in laptop and notebookcomputers, the size constraints of the peripheral bays of such computersmust be considered. In particular, for an internal drive to fit in themajority of laptop and notebook peripheral bays, the drive must be nolonger than 135 mm. The height of the drive must be in the range of 12to 15 mm. These dimensions place many constraints on the design of sucha drive, and give rise to numerous design problems. The presentinvention addresses and overcomes some of the problems presented indesigning a disk drive to these specifications.

A disk drive typically includes an actuator that has heads forinterfacing with a disk cartridge, a head retraction system for movingthese heads to a retraced position, an eject system for ejecting a diskcartridge from the disk drive and an operating system for powering thehead retraction system and the eject system. By way of background ageneral overview of the operation of a disk drive employing thesefeatures is provided.

A disk cartridge is inserted into the disk drive. In order to remove thedisk cartridge from the drive, an eject button disposed on the peripheryof the drive is typically depressed. This button causes the operatingsystem to power the head retraction system. When powered, the headretraction system causes the heads to move away from the disk cartridgeand into a retracted position. After the heads have been retracted theoperating system powers the eject system and ejects the disk cartridgefrom the disk drive.

Due to the limited length and height of a disk drive designed to beincorporated into a lap top computer, each of these systems must operatein a relatively small volume. Furthermore, many of the known prior artsystems cannot be integrated into a disk drive having these limitations.While the eject system, head retraction system, operating system andmotor loading system are advantageous for their intended applications,there is a need for improved systems that can be implemented in lowerprofile disk drives, such as that described above. The present inventionsatisfies these needs.

SUMMARY OF THE INVENTION

An improved disk drive includes an improved operating system, animproved eject system, an improved head retraction system and animproved motor loading system.

An improved operating system for a disk drive includes a motor, a headcrank, an eject crank and an actuator. The actuator selectively linksthe output of the motor to either the head crank or the eject crank.When powered, the head crank causes the heads to be retracted from thedisk cartridge and move to a retracted position. In the retractedposition the likelihood of damage to the heads is decreased.

Similarly, the eject crank can be powered by the output of the motor toeject a disk cartridge from the disk drive.

The actuator selectively controls the output of the motor by movingbetween a first position and a second position. In a first position, theoutput of the motor is linked to the eject crank. When activated, theactuator functions to direct the output of the motor to a secondposition where it is linked to the head crank. In this position, themotor will cause rotation of the head crank and operation of the heads.After the heads have been retracted, the activator functions to couplethe output of the motor back to the first position and to power theeject crank. When powered, the eject crank functions to eject a diskcartridge from the disk drive.

In a preferred embodiment of this invention, the output of the motor islinked to a gear train that can be selectively controlled by theactuator to be directed to either the eject crank or the head crank.Included within this gear train may be an output gear to which either aneject gear disposed on the eject crank or a head gear disposed on thehead crank may be selectively connected. This gear train provides a gearreduction so that the proper torque and speed of the eject crank and thehead crank can be achieved.

The actuator may be an electro-mechanical device that responds tosignals from a typical central processing unit to selectively direct theoutput of the motor to either the eject crank or the head crank.Alternatively, the actuator may be a purely mechanical device thatprovides forces that operate with the force exerted by the rotation ofthe motor to switch the output of the motor between the eject crank andthe head crank.

An improved head retraction system includes a drive link and a trolleythat operate in conjunction with a spring and a head crank to retractthe heads from a disk cartridge. The heads are preferably mounted on acarriage assembly that rides in a groove of a retainer. In a preferredembodiment the trolley engages a post extending from the carriageassembly to hold the carriage assembly to the retracted position. Thehead crank is preferably operated by the improved operating systemdescribed above to move the trolley to a spring loaded position. Powerfrom the head crank is then removed and the trolley is driven by springpressure to contact the post of the carriage assembly and hold it in theretracted position.

In a preferred embodiment, the head crank has a capture feature thatcaptures a wire that links the head crank to a drive link. The drivelink is coupled to the trolley to link the head crank to the trolley.The capture feature includes a groove disposed around a portion of theperiphery of the head crank and a recess in the head crank. The wirepreferably has a shaped end that can mate with the recess. As the headcrank rotates, the wire acts as a cam because it is attached to theperiphery of the head crank.

An improved eject system preferably includes a specially shaped ejectlever, a drag link and an eject crank. The eject lever is rotatablymounted to the disk drive and spring biased to an unloaded position. Thedrag link may be translatably mounted to the disk drive and itinterfaces with the eject lever. The drag link is also spring biased.The drag link interfaces with the eject crank to transmit movement ofthe eject crank to movement of the eject lever.

In particular, the eject lever is rotated by a spring to an unloadedposition when a disk cartridge is not inserted. In this position, theeject lever holds the drag link against spring pressure in a springloaded position. Upon inserting a disk cartridge into the disk drive,the disk cartridge drives the eject lever to rotate against springpressure. When it rotates, the eject lever releases the drag link, whichthen moves due to the force of the spring pressure. After the drag linkhas been moved, it holds the eject lever in its rotated position againstspring pressure.

When an eject button disposed on the disk drive or similar input deviceis depressed, the microprocessor operates to power the operating systemand rotate the eject crank. When the eject crank rotates, it engages thedrag link and moves it against spring pressure. As the drag linkrotates, it releases the eject lever which rotates due to springpressure. The rotation of the eject lever drives the disk cartridge fromthe disk drive. As the eject lever rotates, it engages the drag link andholds it in its spring loaded position.

The eject lever may have a specific shape. For instance, it may bemounted so that it has a portion above the chassis of the disk drive anda portion below the chassis. A single piece is used to allow for theefficient transmission of torque between the two surfaces. In apreferred embodiment, the eject lever is inserted through an aperture inthe chassis and it has a pair of sealing flanges to prevent dust orcontaminants from being transmitted through the aperture. One of thesealing flanges is disposed above the chassis and the other is disposedbelow the chassis. As the eject lever is rotated, the sealing flangesoperate in conjunction to prevent the aperture from becoming uncovered,and they thereby seal the aperture from dust and other contaminants.

According to another aspect of this invention, it employs a motorloading system. This motor loading system permits the moving of a diskdrive motor between an unloaded and a loaded position. In the loadedposition the disk drive motor engages a disk cartridge to rotate astorage medium disposed in the cartridge for retrieving from and storinginformation on the storage medium.

The disk drive motor of this motor loading system may have a threadedexterior. The threaded exterior may be a threaded ring running aroundthe circumference of the disk drive motor. Additionally, this motorloading system may include an aperture in the chassis of the disk drivethat has a threaded ring running around the circumference of theaperture. The disk drive motor can be inserted into this aperture. Uponinsertion, the threads disposed on the disk drive motor can be matedwith those disposed on the threaded motor ring to cause the disk drivemotor to be driven towards the chassis.

The chassis may have a spring extending from the threaded ring, and thedisk drive motor may have a member extending from its periphery forinterfacing with the eject system. This member couples the disk drivemotor to the eject system so that the disk drive motor can be movedbetween an unloaded and a loaded position when a disk cartridge isrespectively ejected and inserted into the disk drive.

When inserting the disk drive motor into the aperture, the member canengage a component of the eject system. This component may be a postextending from the drag link. Upon inserting the disk drive motor, themember may depress the spring. The disk drive motor can then be rotatedto mate the threads of the disk drive motor with the threaded ring. Whenrotated, the member releases the spring.

The spring functions to prevent rotation of the disk drive motor past apredetermined point and thereby prevents the motor from becomingdislodged from the chassis due to mechanical shock or other forces.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric view of a top of a disk drive according to apreferred embodiment of this invention;

FIG. 2 is an isometric view of the bottom of the disk drive of FIG. 1with a circuit board installed;

FIG. 3 is an isometric view of the bottom of the disk drive of FIG. 1with the circuit board removed;

FIG. 4 depicts a disk cartridge adapted for use with a preferredembodiment of this invention illustrated in FIG. 1;

FIG. 5 is a bottom view of the disk cartridge of FIG. 4;

FIG. 6 is a bottom view of the disk drive of FIG. 1;

FIG. 7 is an isometric view of a portion of the head retraction systememployed in the disk drive of FIG. 1 in a first position;

FIG. 8 is an isometric view of the head retraction system of FIG. 7 in asecond position;

FIG. 9 is an isometric view of the head retraction system of FIG. 7 in athird position;

FIG. 10 is an isometric view of a portion of the head retraction systemof FIG. 7;

FIG. 11 is a graph depicting the force provided by the head retractionsystem compared with the force needed to move the heads to a retractedposition;

FIG. 12 is an isometric view of an eject lever according to a preferredembodiment of this invention;

FIG. 13 is an isometric view of the eject lever of FIG. 12 beinginstalled into the disk drive of FIG. 1;

FIG. 14 is a cross-sectional view of a portion of the disk drive of FIG.1 with a disk cartridge installed in the disk drive;

FIG. 15 is a cross-sectional view of a portion of the disk drive of FIG.1 with a disk cartridge being ejected from the disk drive;

FIG. 16 is an isometric view of a portion of the eject system of thedisk drive of FIG. 1 in a first position;

FIG. 17 is an isometric view of the eject system of FIG. 16 in a secondposition;

FIG. 18 is an isometric view of the eject system of FIG. 16 in a thirdposition;

FIG. 19 is an isometric view of a component of the disk drive of FIG. 1;

FIG. 20 is another isometric view of the component of FIG. 19;

FIG. 21 is an isometric view of an operating system of the disk drive ofFIG. 1 according to a preferred embodiment of this invention;

FIG. 22 is a diagrammatical view of the operating system of FIG. 21;

FIG. 23 is an isometric view of the operating system of FIG. 21;

FIG. 24 is a diagrammatical view of an operating system of thisinvention according to another preferred embodiment;

FIG. 25 is another diagrammatical view of the operating system of FIG.24;

FIG. 26 is a third diagrammatical view of the operating system of FIG.24;

FIG. 27 is a schematic diagram of an operating system according to apreferred embodiment of this invention;

FIG. 28 is an isometric view of an operating system of this inventionaccording to a third preferred embodiment;

FIG. 29 is a diagrammatical view of the operating system of FIG. 28;

FIG. 30 is another diagrammatical view of the operating system of FIG.28;

FIG. 31 is an isometric view of a portion of the operating system ofFIG. 28;

FIG. 32 is a diagrammatical view of a portion of the operating system ofFIG. 21 in a first position;

FIG. 33 is a diagrammatical view of a portion of the operating system ofFIG. 21 in a second position;

FIG. 34 is a diagrammatical view of a portion of a motor loading systemaccording to a preferred embodiment of this invention in a firstposition;

FIG. 35 is a diagrammatical view of the portion of the motor loadingsystem of FIG. 34 in a second position;

FIG. 36 is an isometric view of a portion of the motor loading system ofFIG. 1 in a third position;

FIG. 37 is an isometric view of a portion of the motor loading system ofFIG. 1 in a fourth position;

FIG. 38 is an isometric view of a portion of the motor loading system ofFIG. 1 in the position of FIG. 34;

FIG. 39 is an isometric view of a portion of the motor loading system ofFIG. 1 in the position of FIG. 35; and

FIGS. 40 and 40A are enlarged views of a standoff assembly depicted inFIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Introduction

FIGS. 1-3 depict an exemplary disk drive 12 of the present invention.This disk drive 12 can be employed with a microprocessor in either astationary personal computer or a portable personal computer, such as alaptop computer. FIG. 1 is a top isometric view of the disk drive 12with the cover (not shown) of the disk drive removed. FIG. 2 is a bottomisometric view with the circuit board installed, and FIG. 3 is a bottomisometric view of the disk drive 12 with the circuit board removed. Thedisk drive 12 comprises a chassis 14 having u-shaped outer edges thatform opposed guide rails 12 a, 12 b that guide a removable diskcartridge into the disk drive 12 through an opening 22. In the presentembodiment, the chassis 14 is metallic.

A cartridge shutter lever 28 and an eject lever 302 are rotatablymounted on the chassis 14. Both of the levers 28, 302 are shown in FIG.1 in the positions that they occupy when a disk cartridge is fullyinserted into the disk drive 12. During cartridge insertion, the shutterlever 28 and the eject lever 302 swing from a forward position to theposition shown in FIG. 1. During this movement, an abutment surface onthe shutter lever 28 engages a shutter 18 of the disk cartridge 10,depicted in FIGS. 4 and 5, and moves the shutter 18 to the side,exposing a head access opening 30 in the front peripheral edge of thecartridge 10.

As mentioned above, the eject lever 302 also moves from a forwardposition to the position shown in FIG. 1, when a disk cartridge 10 isinserted. In the position shown in FIG. 1, the eject lever 302 is heldin a cocked position against spring tension. When it is desired to ejecta disk cartridge 10 from the drive 12, an eject button 13 is pushed.Among other things, this causes the eject lever 302 to be released fromits cocked position, so that it springs forward to force the diskcartridge to eject out of the disk drive 12.

The disk drive 12 also has a linear actuator 17 disposed at the rear ofthe chassis 14. The linear actuator 17 comprises a carriage assembly 32,an outer magnet return path assembly 34, and two inner return paths 36a, 36 bdisposed on opposite sides of the carriage assembly 32. After adisk cartridge 10 is inserted into the disk drive 12, the carriageassembly 32 carries a pair of read/write heads 38 over the recordingsurfaces of a disk-shaped storage medium within the cartridge. A spindlemotor 40 is provided on the floor of the chassis 14. During cartridgeinsertion, the spindle motor 40 is translated vertically into engagementwith a hub 16 of the disk cartridge 10, in order to rotate thedisk-shaped storage medium at a relatively high speed. A circuit board11 is attached to the chassis 14 via a plurality of standoffs (notshown). The circuit board 11 carries the drive circuitry. A gear train52 controls movement of the eject lever 302 and movement of a headretraction system 42 that moves the carriage assembly 32 to a parkedposition to prevent damage to the read/write heads 38, when the diskdrive is not in use.

FIGS. 4 and 5 depict an exemplary disk cartridge 10 adapted for use inthe disk drive 12 of this invention. In a preferred embodiment, the diskcartridge 10 may be a ZIP™ disk cartridge produced by IomegaCorporation. However, the disk drive 12 of this invention is not limitedto these disk cartridges and a variety of other standard disk cartridgesmay be employed with various features of the disk drive of thisinvention. As shown, the exemplary disk cartridge 10 has an upper and alower shell 22, 24 that mate to form an outer casing 15. In a preferredembodiment, the shells 22, 24 are plastic. Rotatably mounted in thecasing 15 is a hub 16. A disk shaped information storage medium 13 isaffixed to the hub 16. In a preferred embodiment, the storage medium 13is a flexible magnetic storage medium. However, in other embodiments,the storage medium may be a rigid magnetic disk, a magneto-optical diskor an optical storage medium. An opening 21 in the lower shell 22 of thecasing 15 provides access to the disk hub 16. A head opening 30 in thefront peripheral edge of the disk cartridge 10 provides access to thesurfaces of the storage medium 13 for the read/write heads 38 of thedisk drive 12.

As depicted in FIG. 2, a shutter 18 is also provided on the frontperipheral edge of the disk cartridge 10 to cover the head accessopening 30 when the cartridge 10 is not in use. When a disk cartridge 10is inserted into the disk drive 12, the shutter 18 moves to the side andexposes the head access opening 30. This provides access for theread/write heads 60 to the storage medium 13.

As is known in the art, a typical disk drive has an eject system forejecting a disk cartridge from a disk drive. A typical disk drive alsocontains a head retraction system for holding the disk drive heads in aretracted position with respect to a disk cartridge. In this retractedposition, the heads are typically disposed in the rear of a disk driveto minimize the likelihood of damage to the heads through accidentalcontact. In addition to having an eject system and a head retractsystem, a typical disk drive has an operating system for controlling theoperation of the eject system and the head retraction system. Moreover,a conventional disk drive may have a motor system for engaging the diskdrive motor with the disk cartridge hub. The disk drive of thisinvention includes an improved head retraction system 42, an improvedeject system 44, an improved operating system 46 and an improved motorloading system.

Standoff Assembly

As mentioned above, FIG. 2 is a bottom view of the disk drive 12. Theprinted circuit board 11 and chassis 14 are mechanically coupled inaccordance with the present invention. At least one standoff 500 isshown coupled between the printed circuit board 11 and chassis 14. Themethod of coupling the standoff is discussed below.

FIGS. 40 and 40A illustrate the preferred embodiment of the standoffassembly 500 and how it is coupled between the printed circuit board 11and chassis 14. The standoff assembly 500 comprises an printed circuitboard receptacle 502 and a chassis receptacle 504. The printed circuitboard receptacle 502 and chassis receptacle 504 are adapted to becoaxially aligned and coupled thereto.

The printed circuit board receptacle 502 has a first sidewall 504 with afirst open end 506 and a second open end 508 with a bore 510 extendingtherebetween. The first open end 506 is adapted to be soldered to a padon the printed circuit board 11 adjacent to a receiving hole 510 formedin the circuit board 11 to enable a fastening member 512 to passtherethrough. Preferably, the circuit board 11 receptacle is made of acooper material.

The chassis receptacle 504 comprises a second sidewall 514 with aproximal open end 516 and a distal open end 518 with a second bore 520extending therebetween. Preferably, the second bore 520 is threaded andadapted to receive a screw having a screw head 522. The proximal end 516of the chassis receptacle 504 is coupled or integrally formed to thechassis 14 such that the circuit board receptacle second end 508 cancoaxially cooperate with the distal end 518 of the chassis receptacle504. In this position, the screw 520 can be threaded through the secondbore 520 such that the printed circuit board and chassis are coupledtogether. Preferably, the first end 506 of the circuit board receptacleis formed such that the screw head 522 is relatively flush or below theprinted circuit board when the screw is threaded through each bore suchthat the screw head does not substantially extend out and away from thecircuit board.

It is noted that the standoffs can be adapted to receive other types offasteners without threads can be employed such that the head isrelatively flush with the printed circuit board. Additionally, althoughfour standoff assemblies are shown to attach the circuit board to thechassis. It is noted that the number of standoffs employed may depend onthe size and shape of the circuit board and chassis.

An Improved Operating System for an Eject System and a Head RetractionSystem of a Disk Drive

Depicted schematically in FIG. 27 is an improved operating system 46 foran eject system 44 and a head retraction system 42. This operatingsystem 46 may include an eject button 13, an electrical switch 200, amicroprocessor 202, a motor 50, a gear train 52, an eject crank 56 and ahead crank 54. The eject button 13 may be disposed on the front of thedisk drive 12, as depicted in FIGS. 1-3. Extending from the eject button1-3 may be a member 204 that interfaces with an electrical switch 200.The electrical switch 200 is of a conventional type and is mated andunmated in response to operation of the eject button 13. Preferably,this electrical switch 200 is disposed on the circuit board 11 withinthe disk drive 12 depicted in FIG. 2. The microprocessor 202 is also ofa conventional type and is in electrical communication with theelectrical switch 200. The motor 50, the gear train 52, the eject crank56 and the head crank 54 are disposed within the disk drive 12. Themotor 50 is in electrical communication with the microprocessor 202 andoperates in response to signals received from the microprocessor 202.The motor 50 powers the gear train 52 and can selectively power eitherthe eject crank 56 or the head crank 54.

By way of overview, when a disk cartridge 10 is inserted into the diskdrive 12 and the eject button 13 is depressed, the member 204 translatesto close the electrical switch 200. With the switch 200 closed, themicroprocessor 202 sends an electrical signal to the motor 50, whichcauses the motor 50 to rotate. Rotation of the motor 50 drives the geartrain 52. The motor 50 is then selected to power either the eject crank56 or the head crank 54 and thereby eject a disk cartridge 10 from thedisk drive 12 and move the head retraction system 42. Although an ejectbutton 13, a member 204 and an electrical switch 200 may be used tocommunicate a signal to retract the heads 38 and to eject a diskcartridge 10 a variety of other systems may be employed to communicatesuch a signal to the microprocessor 202.

As is illustrated in FIGS. 19 and 20, the eject crank 56 has a collar206 disposed around its axis. The periphery of the collar 206 isgenerally circular, but a portion of the periphery is flat 207 andengageable with a pair of contacts 209 mounted to the disk drive 12 andextending in a plane parallel to the chassis 14, as viewed in FIGS.21-23. The contacts 209 are spring loaded so that they are in an unmatedposition. When the contacts 209 are engaged with the circular portion ofthe collar 206, they are pushed together in a mated position. As theeject crank 56 rotates, the flat portion 207 engages the contacts 209and they spring apart and become unmated. These contacts 209 interfacewith the microprocessor 202 to control the operation of the eject crank56. The eject crank 56 may also have a finger 55 extending from a topsurface for engaging the eject system 44. This eject finger 55 ispreferably disposed off the center of the eject crank 56, so that it canfunction as a cam when engaged with the eject system 44.

As mentioned above, the operating system 46 also includes a motor 50,which drives the gear train 52 to operate either the head crank 54 orthe eject crank 56. This motor 50 may be a fractional horse power motor50 and in a preferred embodiment it is rated at about 300 g-cm at 30revolutions per minute (rpm) and about 100 g-cm at 10 rpm. The motor 50rotates an output shaft to which a worm gear 51 is preferably attached.The worm gear 51 engages the gear train 52, as is described in furtherdetail below, to drive either the head crank 54 or the eject crank 56.Although a worm gear 51 is employed as the drive gear in a mostpreferred embodiment, other gearing systems may be employed to convertthe rotation of the motor output shaft to rotation of the gear train 52.

A variety of gear trains 52 may be employed with this invention to linkthe motor 50 to either the eject crank 56 or the head crank 54. In apreferred embodiment the gear train 52 includes a first gear 210 that isdriven by the worm gear 51. A second gear 212 is rotatably mounted onthe same shaft as the first gear 210 and therefore, it will rotate inresponse to rotation of the worm gear 51. A third gear 214 is rotatablymounted to the disk drive 12 and is engaged with the second gear 212.The diameter of the second gear 212 is smaller than that of the firstgear 210, and therefore they provide a speed reduction when engaged withthe third gear 214. A pair of output gears, the fourth 216 and fifth 218gears, are rotatably mounted about a common shaft. The fourth gear 216has a larger diameter than the fifth gear 218. Moreover, the fourth gear216 is engageable with the head gears 220 to drive the head crank 54,while the fifth gear 218 is engageable with the eject gear 57 to drivethe eject crank 56. The fourth gear 216 is also engageable with thethird gear 214.

In addition to be rotational about their shaft, the fourth 216 and thefifth gear 218 are also mounted on an end of a shift arm 103, asdepicted in FIGS. 32 and 33. This shift arm 103 is rotatably mountedabout the axis of the third gear 214. Thus, the fourth 216 and the fifth218 gears have freedom of movement in two degrees. They can rotate abouttheir own shaft, and they can rotate on the shift arm 103 about thecenter of the shaft of the third gear 214.

An eject gear 57 is mounted about the axis of the eject crank 56. Thiseject gear 57 is engageable with the fifth gear 218. In contrast, thehead crank 54 has a first 224 and a second head gear 226 mounted about acommon shaft and a third head gear 62 mounted on the head crank 54. Thefirst head gear 224 is engageable with the fourth gear 216 and thesecond head gear 226 drives the third head gear 62 and the head crank 54to rotate. The gearing is different for the head crank 54 and the ejectcrank 56 so that the proper torque and speed can be applied to each androtate the respective cranks at their rated speed.

Also included within this operating system 46 is a switching mechanism230 for switching the output of the motor 50 to either the head crank 54or the eject crank 56. In the preferred embodiment illustrated in FIGS.32 and 33, the switching mechanism 230 includes an electrical mechanicalactuator 58 and a pair of toggle members 100, 101. This electricalmechanical actuator 58 may be a voice coil motor, solenoid or similarelectrical mechanical device. In a preferred embodiment, the actuator 58is a voice coil motor rated at about 4.5 volts and 80 milliamperes. Theactuator 58 is mechanically linked to the fourth 216 and fifth gears 218to direct the output of the motor 50 to either the head crank 54 or theeject crank 56.

In a preferred embodiment, this mechanical linkage includes two togglemembers 100, 101 that are spring biased by a biasing spring 102. Thefirst toggle member 100 is preferably rotatably mounted about the axisof the eject crank 56 and is attached to the actuator 58. Since theactuator 58 is mechanically coupled to the first toggle member 100, theactuator 58 is also rotatably mounted about the axis of the eject crank56. The method of attaching the first toggle member 100 to the actuator58 may be welding, fasteners, adhesives or other known fasteningtechniques. The second toggle member 101 is rotatably mounted about theaxis of the third and fourth gears 214, 216. In addition, the togglemembers 100,101 are connected at a movable pivot point, so that they canrotate relative to each other. This connection between the first and thesecond toggle members may be rivets or the like. Since the second togglemember 101 is rotatably mounted to the axis of the third and fourthgears 214, 216, it can move with the shift arm 103.

A biasing spring 102 is also provided which biases the toggle members100, 101. More particularly, this spring 102 is mounted to the diskdrive 12 and is connected to the first toggle member 100 to bias thefirst toggle member 100 to rotate in the clockwise direction. Incontrast, the second toggle member 101 is biased to rotate in thecounter clockwise direction.

In operation the operating system 46 functions to selectively power boththe head crank 54 and the eject crank 56 from a single motor 50. Whenthe eject button 13 is depressed, it causes the electrical switch 200 tomate, as described above. In response to the mating of the electricalswitch 200, the microprocessor 202 sends a signal to the motor 51 andthe motor 51 is powered. Initially, in response to an electrical signal,the actuator 58 rotates in the counter clockwise direction about theaxis of the eject crank 56 from its initial state depicted in FIG. 32.This rotation occurs against spring pressure provided by the biasingspring 102. As the actuator 58 rotates, so does the mechanically linkedfirst toggle member 100. The first toggle member 100 rotates counterclockwise, and the connected second toggle member 101 rotates in aclockwise direction. When the toggle members 100, 101 rotate, they moveinto a more obtuse angular relationship with respect to each other.

As mentioned above, the fourth 216 and fifth gears 218 are free to moveand are not fixed to the disk drive 12. Since the fourth 216 and fifth218 gears are connected by the shift arm 103 to third gear 214, theyrotate about the axis of the third gear 214 as the second toggle member101 is rotated. Thus, when the second toggle 101 begins to rotate andthe toggles 100, 101 move into a more obtuse angular relationship thefourth and fifth gears 206 move away from the eject crank and towardsthe head crank 54. Eventually, the fifth gear 218 disengages from theeject gear 57, and the fourth gear 216 engages the first head gear 224,as depicted in FIG. 33. Thus, through operation of the actuator 58, thefourth gear 216 can be mechanically linked to the head crank 54 and,thereby mechanically linking the output of the motor 50 to the headcrank 54.

In addition to providing electrical power to the actuator 58, electricalpower is also provided from the microprocessor 202 to the motor 50. Asthe motor 50 is powered it drives a gear, which is preferably the wormgear 51 described above. This worm gear 51 then engages the gear train52 and through the gear train 52 described above rotates the fourth gear216. Since the fourth gear 216 is engaged with the first head gear 224,it causes rotation of the head crank 54 about its axis. Preferably, themotor 50 rotates in a direction which causes the head crank 54 to rotatein a clockwise direction as viewed in FIGS. 3, 6 and 21. Rotation of thehead crank 54 together with the head retraction system 42 describedbelow causes the head retraction system 42 to move to a retractedposition.

As described below, though contacts, a sensor or a similar device themicroprocessor 202 will determine that the head crank 54 has beenrotated and power should be removed from the head crank 54. Upondetermining this, the microprocessor 202 will cause the motor 50 torotate in the opposite direction and remove power from the actuator 58.When electrical power is removed from the actuator 58, the biasingspring 102 will cause the actuator 58 to return to its originalposition. This occurs because as described above when power from theactuator 58 is removed, the force it applies decreases and eventuallythe force from the biasing spring 102 overcomes the decreasing forceapplied from the actuator 58. When this occurs, the biasing spring 102causes the first toggle member 100 to rotate in a clockwise directionabout the eject crank axis. This causes the second toggle member 101 torotate in a counter clockwise direction and the first and second togglemembers 100, 101 to move into a more obtuse angular relationship withone another. As this occurs, the fourth gear 216 becomes disengaged fromthe first head gear 224 and the fourth 216 and fifth 218 gears rotatetowards the eject gear 57, as depicted in FIG. 32. Eventually, the fifthgear 218 engages the eject crank gear 57.

Since electrical power is still being provided to the motor 50, themotor 50 is still driving the worm gear 51 and the gear train 52. Thus,with the gear train 52 now mechanically linked to the eject crank 56,the motor 50 will now drive the eject crank 56 to rotate in a counterclockwise direction as viewed in FIGS. 3 and 6.

As the eject crank 56 rotates, two functions occur. First, the ejectcrank 56 interacts with several of the components of the eject system 42to eject a disk cartridge from the disk drive. In addition, theoperation of the contacts 209 is controlled by the rotation of the ejectcrank 56. As the eject crank 56 rotates and reaches about the 8 o'clockposition as viewed in FIG. 22 and about the 4 o'clock position as viewedin FIG. 3, the rounded surface of the collar 206 of the eject crank 56engages the contacts 209 and drives them together. This position isabout where the finger 55 engages the drag link 304. Upon mating, themicroprocessor 202 receives a signal informing it that the eject crank56 is rotating and has begun to drive the drag link 304. The eject crank56 will continue to rotate with the rounded surface of the eject crank56 engaging the contacts 209. At about the 12 o'clock position as viewedin FIG. 3 (3 o'clock as viewed in FIG. 22) the eject crank 56 will havedriven the drag link 304 to its rear most position and further rotationof the eject crank 56 will no longer drive the drag link 304. At aboutthe 7 o'clock position as viewed in FIG. 3 (10 o'clock as viewed in FIG.22), the flat surface 207 of the collar 206 will again engage thecontacts 209. Spring pressure will allow the contacts to unmate. In theunmated position the contacts 209 send a signal to the microprocessor202 indicating that the eject crank 56 has driven the drag link 304 andhas rotated enough so that the finger 55 is clear of the path of thedrive link 304 so that the drive link 304 can translate forward when adisk cartridge 10 is inserted into the disk drive 12.

Thus, in summary through a single motor 50, an actuator 58 and a geartrain 52 two functions are achieved. The eject crank 56 is rotated toeject a disk cartridge 10 from the disk drive 12 and a head crank 54 isoperated to hold the heads 38 in a retracted position.

In another preferred embodiment of this invention, the gear train 52 isvaried slightly. Preferably, this gear train 52 provides a gearreduction between the motor and the eject crank 56 or the head crank 54.In a preferred embodiment, the gear train 52 includes, as shown in FIGS.24 and 25, two sets of gears between the worm gear 51 and the outputgears. The first set of gears includes a first gear 210 and a secondgear 212. The first gear 210 is of larger diameter then the second gear212, and they rotate about the same axis. The first gear 210 interfaceswith the worm gear 51 driven by the motor 50. A third gear 214 ismounted to the disk drive and driven by the second gear 212. A fourthgear 216 and an output gear 219 are mounted on a common shaft, and theoutput gear 219 has a larger diameter than the fourth gear 216. Thefourth gear 216 mates with the third gear 214, while the output gear 219mates with either the eject gear 57 or the head gear 62. The fourth gear216 and the output gear 219 may also be mounted on a shift arm 103 thatis pivotally mounted about the axis of the third gear 214. Thus, in thisembodiment the output gear 219 has freedom of movement in two degrees,rotationally about its own axis and rotationally about the axis of thethird gear 214. Disposed on the eject crank 56 is an eject gear 57 anddisposed on the head crank 54 is a head gear 62. The importance of usinga gear train 52 of this type because it allows for the proper speedreduction between the output of the motor and each of the cranks.

In this preferred embodiment, the electrical mechanical actuator 58 issimilar to that described above and may be a voice coil motor. Insteadof being rigidly attached, in this embodiment, the first toggle member100 mates with the actuator 58 in a cam and follower arrangement, asdepicted in FIGS. 24 and 25. The actuator 58 acts as the cam and thefirst toggle member 100 as the follower. In a preferred embodiment, theactuator 58 has a cammed mating surface that mates with a followersurface of the first toggle member 100. The follower surface isconstructed so that when the cammed surface contacts it, a portion ofthe follower surface will remain in contact with the cam surface as theactuator 58 drives the first toggle member 100. Similar to theembodiment described above, the first toggle member 100 is pivotallymounted about the axis of the eject crank 56. In this embodiment, thesecond toggle member 101 is again pivotally connected to the firsttoggle member 100 and rotatably connected to the shaft of the outputgear 219.

In its initial state, the output gear 219 is linked to the eject gear 57to drive the eject crank 56, as depicted in FIG. 24. When the ejectbutton 13 is depressed, it causes the electrical switch 200 to mate, asdescribed above. In response to the mating of the electrical switch 200,the microprocessor 202 sends a signal to the motor 51 and the motor 51is powered. Initially, in response to an electrical signal, the cammedsurface of the actuator 58 engages the follower surface of the firsttoggle member 100 and causes it to rotate in a counter clockwisedirection about the axis of the eject crank 56. This rotation occursagainst spring pressure provided by the biasing spring 102. As the firsttoggle member 100 rotates counter clockwise, the second toggle member101 rotates in a clockwise direction. When the toggle members 100, 101rotate, they move into a more obtuse angular relationship with respectto each other.

As the toggle members 100, 101 rotate, they cause the output gear 219 torotate on the shift arm 103 about the axis of the third gear 214. Theoutput gear 219 rotates on the shift arm 103 until it engages the headgear 62 disposed on the head crank 54, as depicted in FIG. 25. Whileengaged, the motor 50 powers the head crank 54. Upon receiving anelectrical signal indicating that the head crank 54 no longer needs tobe rotated, the power is removed from the actuator 58 and the biasingspring 102 causes the output gear 219 to rotate on the shift arm 103away from the head crank 54 and to the eject crank 56. Upon engagementwith the eject gear 57, the output gear 219 drives the eject crank 56 torotate. Although not shown in this embodiment, contacts 209 may bedisposed to operate in conjunction with a collar 206 disposed on theeject crank 56 as described above to control the motor 50.Alternatively, a timer or similar device may be employed.

Another preferred embodiment of the operating system 46 is depicted inFIGS. 28-31. In this embodiment, the operating system 46 of the diskdrive 12 also includes a motor 50, a gear train 52, an eject crank 56and a head crank 54. Although the motor 50 in this embodimentselectively powers both the eject crank 56 and the head crank 54, anelectrical mechanical actuator is not needed in this embodiment. Rather,the switching device in this embodiment is purely a mechanical actuator58 that operates similar to a brake and clutch to switch the output ofthe motor 50 between the eject crank 56 and the head crank 54. In apreferred embodiment the actuator 58 is a clip.

The gear train 52 in this embodiment includes a first 210 and a secondgear 212 rotatably mounted about a common shaft with the first gear 210having a larger diameter than the second gear 212. The first gear 210mates with the worm gear 51 driven by the motor 50. A third 214 and afourth gear 216 are also mounted about a common shaft. The third 214 andfourth gears 216 are not fixed to the disk drive 12. Rather, they aremounted on a shift arm 103 that is rotatably mounted about the axis ofthe first and second gears 210, 212. Thus, the third 214 and fourth 216gears have freedom of movement in two degrees. They can rotate abouttheir own axis and they can also revolve around the shaft of the firstand the second gears 210, 212.

The third gear 214 has a larger diameter than the fourth gear 216, andthe third gear 214 mates with the second gear 212. The fourth gear 216is selectively engaged with either the eject gears 222 or the head gears220. The eject gears 222 include a first 223, a second 225 and a third57 eject gear. The first 223 and the second 225 eject gears are mountedabout a common shaft with the first eject gear 223 having a largerdiameter than the second eject gear 225. The third eject gear 57 isdisposed about the periphery of the eject crank 56. The first eject gear223 is engageable with the fourth gear 216 and the second eject gear 225engages the third eject gear 57 to drive the eject crank 56. The headgears 220 include a first head gear 224 that is engageable with thefourth gear 216, and a second head gear 62 disposed on the periphery ofthe head crank 54 that is engageable with the first head gear 224.

As alluded to above, the actuator 58 in this embodiment is a clip, as isbest seen in FIG. 31. The clip is affixed to the shaft of the first andsecond gears 210, 212 and the shaft of the third and fourth gears 214,216. This clip may have two openings 105 disposed along its longitudinalaxis for affixing the clip to these shafts. Although clipping is thepreferred method of attachment, other forms of fastening, including butnot limited to, are an interference fit and a threaded connection. Theclip may also have a first and a second spring member 107 extending atan angle from its longitudinal axis at the end of the clip disposed onthe shaft of the third and fourth gears 214, 216. At the end of bothspring members 107 is a bar 109 that rests upon the surface of theoutput gear 219. The clip is preferably attached so that it pushes down,as viewed in FIG. 28, with a normal force upon the surface of the thirdgear 214. This force is applied by the bars 109.

The clip functions to engage the fourth gear 216 with either the ejectcrank 56 or the head crank 54 as follows. With a disk cartridge 10inserted into the disk drive 12, the fourth gear 216 is engaged with thefirst eject gear 223 as shown in FIG. 30. Rotation of the motor 50causes, the worm gear 51 to drive the first gear 210 to rotate. As thefirst gear 210 is powered by the worm gear 51, a torque is generatedthat is equal to the product of the radius R₁ and the force F₁ exertedby the worm gear 51 on the first gear 210.

As mentioned above, the clip 58 is exerting a normal force F_(n)downward on the third 214 and fourth 216 gears. Because this normalforce F_(n) pushes down with a force great enough to compress the third214 and fourth 216 gears between the clip and the disk drive 12, thethird and fourth gears 214, 216 resist rotating. Alternatively stated,the clip operates similar to a break in that it creates a frictionalforce by compressing the third 214 and fourth 216 gears so that theyresist rotating. The resistance to rotation can be expressed as a forceF₂ that is tangential to the second gear 212 in a plane perpendicular tothe normal force F_(n). This force F₂ creates a torque T₂ equal to theproduct of F₂ and the radius R₂ of the second gear 214 that resistsrotation of the second gear 214.

Initially, the worm gear 51 drives the first and second gears 210, 212to rotate in a counter clockwise direction as viewed in FIGS. 28 and 29.When the first gear 210 is powered with the driving torque T₁ equal tothe product of F₁ and R₁, the torque T₂ generated by the normal force ofthe clip opposes the driving torque, as viewed in FIG. 29. As long asthe torque T₁ is greater than the torque T₂, the third 214 and fourth216 gears are driven to rotate about the axis of the first 210 andsecond 212 gears on the shift arm 103. As they rotate, the fourth gear216 moves away from the first eject gear 223 and engages the first headgear 224, as shown in FIG. 29. When engaged with the first head gear224, the torque T₂ increases due to engagement with the head gears 220greater than the magnitude of T₁. With T₂ greater than T₁, the third 214and fourth 218 gears no longer rotate about the axis of the first 210and second 212 gears, and they now rotate about their own axis. As theyrotate about their own axis, the head gears 220 are driven to rotate andthe head crank 54 is powered. When powered, the head crank 54 operatesin conjunction with the head retraction system 42 described below.

In this embodiment, the motor 50 is reversible and when the headretraction system 42 sends a signal indicating that power should beremoved from the head crank 54, the microprocessor 202 sends a signal tothe motor 50 to cause it to reverse its direction of rotation. As themotor 50 rotates in the opposing direction, the torques T₁ and T₂ changedirection. In this direction, the torque T₂ is greater than the torqueT₁ and therefore, the third and fourth gears 214, 216 are driven torotate on the shift arm 103 away from the head gears 220. As they rotateon the shift arm 103, the third and fourth gears 214, 216 stop rotatingabout their own axis. The shift arm 103 eventually rotates the third andfourth gears 214, 216 so that the fourth gear 216 engages the firsteject gear 223, as shown in FIG. 30. Upon engaging the first eject gear223, the torque T₂ increases and the third and fourth gears 214, 216 areprevented from rotating on the shift arm 103. In this position, thethird and fourth gears 214, 216 rotate about their own axis, and thefourth gear 216 powers the eject gears 222 to rotate the eject crank 56and thereby eject a disk cartridge 10 from the disk drive 12 asdescribed above.

It is important to appreciate the selection of the proper spring andforce to be exerted by the actuator 58. If the force is not great enoughin magnitude, friction between the shift arm 103 and the disk drive 12will prevent the third and fourth gears 214, 216 from rotating theentire distance from the head gears 220 to the eject gears 222. Moreparticularly, the shift arm 103 would stop midway between the head gears220 and the eject gears 222 and begin spinning idly without engagingeither the eject gears 222 or the head gears 220.

For several reasons (including disconnecting the source of electricalpower) electrical power to the motor 50 can be removed during operationof the gears 52. If the output of the motor 50 is linked to the headgears 220, it is important to disengage the head gears 220 to releasethe components of the head retraction system 42 that the head crank 54drives. In order to disengage the head gears 220 from the motor 50, asensor and a capacitor are provided on the circuit board 11. The sensordetects a loss of electrical power to the motor 50 and the capacitor hassufficient power to operate the motor 50 for several turns. Ifelectrical power is lost while the motor 50 is linked to the eject gears220, the capacitor will drive the motor 50 to rotate in the reversedirection. Upon reversing its direction of rotation, the change indirection of the torque T₁ causes the third and fourth gears 214, 216 torotate on the shift arm 103 and to disengage the motor 50 from the headgears 220.

In this embodiment, a single motor 50 can power either the eject system44 or the head retraction system 42. By reducing the need for anelectrical mechanical actuator 58, additional cost savings are achieved.Furthermore, the size of the operating system 46 can be reduced and theelectrical power needed to operate the operating system 46 may bereduced.

An Improved Head Retraction System of a Disk Drive

According to a preferred embodiment of this invention, an improved headretraction system 42 includes a head crank 54, a drive link 70, atrolley 78 and a linear actuator 16, as illustrated in FIGS. 1 and 6.These components operate in conjunction to hold the heads in a retractedposition when a disk cartridge 10 is ejected from the disk drive 12.

By way of overview, the linear actuator 16 is mounted within the diskdrive 12 so that it can move linearly or approximately parallel to thechassis as shown in FIG. 1. Although the actuator 16 moves substantiallyparallel to the chassis, the actuator 16 may move in either of theplanes perpendicular to the chassis. The linear actuator 16 includes acarriage assembly 32, a load beam 60, a head gimbel assembly 61 andheads 38 The load beam 60 is preferably welded to the head gimbelassembly 61, and the heads 38 are mounted on an end of the head gimbelassembly 61. The load beam 60, the head gimbel assembly 61 and the heads63 are all mounted on the carriage assembly 32. As can be seen in FIG.1, the carriage assembly 32 is translatably mounted in the disk drive12. In particular, the carriage assembly 32 is free to translate towardthe front and the back of the disk drive 12. Preferably, the carriageassembly 32 has a rod (not shown) mounted through the assembly 32 uponwhich the carriage assembly 32 translates.

The head retraction system 42 preferably has a retainer 65 mounted tothe underside of the chassis 14, as depicted in FIGS. 3 and 6-9. Theretainer 65 may be affixed to the chassis 14 with a variety of knownfastening techniques, including threaded fasteners. In a preferredembodiment, the retainer 65 is constructed from transparent plastic sothat different portions of the retraction system 42 are visible formaintenance and other purposes. Disposed within the retainer 65 is agroove 67 running from the front of the retainer to the back of theretainer. The carriage assembly 32 translates in this groove. Moreparticularly, the carriage assembly 32 has a post 69 extending from theassembly 32 above the groove 67, down through the groove 67 and belowthe groove 67. In a preferred embodiment, this post 69 has a triangularcross section and a flat portion running perpendicular to the groove 67for engagement with the trolley 78.

As shown in FIGS. 9 and 10, the head crank 54 includes a head gear 62and a cylindrical member 64 both mounted around a center of the headcrank 54. The head gear 62 transmits power from the operating system 46,as described above, to power the head crank 54. In addition, the headcrank 54 has a circumferential groove 71. In a preferred embodiment thisgroove 71 extends around a portion of the periphery of the head crank54, and in the preferred embodiment depicted, the groove 71 extendsabout 270° around the periphery of the head crank 54. As is depicted inFIGS. 21 and 23, a recess 73 used in conjunction with the wire 68described below is disposed within the groove 71. The recess 73 ispreferably disposed away from the center of the head crank 54, so thatthe wire 68 can act as a cam, as is discussed below in further detail,when the head crank 54 rotates.

The bottom portion of the head crank 54 may have the shape depicted inFIGS. 7-10, 21 and 23. This shape includes a sold circular section 75and a head finger 77. This shape allows for mounting the wire 68 in therecess 73 and permitting the wire 68 to rotate about the periphery ofthe head crank 54.

A wire 68 or similar device is attached to the head crank 54 at thegroove 71. More particularly, one of the longitudinal ends of the wire68 has a hook shaped end 88, as is best seen in FIG. 7. This hook shaped88 end can be fitted through the circumferential groove 71 and set intothe recess 73. Because the other longitudinal end of the wire isconnected to the drive link 70, the wire 68 connects the head crank 54to the drive link 70. As shown in FIGS. 7-10, the wire 68 preferablyextends through a cavity 81 in the drive link 70. The wire 68 is affixedto the drive link 70 by a profiled end. In a preferred embodiment, thisprofiled end 90 approximates the shape of an “s.” Other known methods ofattachment may be employed.

As is best shown in FIGS. 7-10, the drive link 70 is rotatable mountedto the disk drive 12 between its longitudinal ends. A finger 72 isdisposed on one axial end of the drive link 70. Connected to the finger72 is a head spring 74, which is fixed at its other end to the diskdrive 12. Although in a preferred embodiment, the drive link 70 isattached to the head spring 74 with a finger 72, a variety of otherattachment means may be employed. Since the head spring 74 is fixed tothe disk drive 12, it biases the drive link 70 to rotate in theclockwise direction as viewed in FIGS. 6-10.

The trolley 78 is mechanically connected through any of a variety ofknown fastening means including, but not limited to, an interferencefit, a slide and groove and fasteners, to the drive link 70. In apreferred embodiment, the trolley 78 has a post (not shown) runningbetween its upper and lower surfaces and an opening at its axial endclosest to the drive link 70. The longitudinal end of the drive link 70closest to the trolley 78 also has a means for attaching to the trolley78. In a preferred embodiment, the means is a circular shaped openingcan be press fit around the post of the trolley 78. In addition to beingattached to the drive link 70, the trolley 78 is slidably connected tothe groove 67 of the retainer 65. In particular, the other axial end ofthe trolley 78 is generally circular in shape and has a circumferentialopening 77 running between the top surface and the bottom surface of thetrolley 78. The retainer 65 extends into this opening 77 and the top andthe bottom surfaces extend over the retainer 65 so that the trolley 78is mounted on the groove 67, but is free to translate within the groove67.

The trolley 78 has freedom of movement in two degrees. In particular,the axial end of the trolley 78 connected to the drive link 70 is freeto rotate about the center of the circular section of the other axialend. In addition, the circular shaped axial end is free to translatelinearly in the groove 67 of the retainer 65. Thus, the trolley 78 cantranslate within the groove 67 and rotate about the center of one of itsaxial ends while translating.

As can be seen in FIGS. 7-10, the drive link 70 and the trolley 78 aremounted so that they can move in an angular relationship with respect toeach other. This occurs because the trolley 78 and the drive link 70 arerotatably mounted at one end and are fixed to each other at theirrespective opposing ends. Upon inspection of FIG. 7, it can be seen thatif the carriage assembly traverses the entire length of the groove, thehead crank will only rotate about 180.

Through operation of the components described above, the disk driveheads 38 and the carriage assembly 32 can be held in a retractedposition in the back of the disk drive 12. In an initial positiondepicted in FIGS. 6 and 7, the drive link 70 and the head crank 54 arespring biased by the head spring 74. Consequently, the drive link 70 andthe trolley 78 are disposed at an angular relationship of about 180°. Inthis position, the heads 38 are in a retracted position because they arein the back of the disk drive 12.

As alluded to above, in a preferred embodiment the trolley 78 is notfixed to the carriage assembly 32. Rather, they are both free totranslate in the groove 67. Additionally, the trolley 78 is preferablymounted forward of the carriage assembly 32. Thus, if the trolley 78translates towards the back of the disk drive 12 it will push thecarriage assembly 32, and forward movement of the trolley 78 will noteffect the placement of the carriage 32 in the groove 67. In contrast,backward movement of the carriage assembly 32 will not effect theposition of the trolley 78. When a cartridge is inserted into the diskdrive 12, the head retraction system 42 is operated as described belowto move the trolley 78 to the forward part of the groove so that thecarriage assembly 32 is free to translate in the forward direction.

The head retract system 42 may also include a contact 84 disposedforward of the carriage assembly 32, as is depicted in FIGS. 7-10. Thiscontact 84 interacts with a protrusion 86 extending from the drive link70 to control operation of the head crank 54. In particular, when thedrive link 70 is in the position illustrated in FIGS. 9 and 10, theprotrusion 86 closes the contacts 84 and thereby causes an electricalsignal to be sent to the microprocessor 202 indicating that the drivelink 70 has been rotated to its most forward position. Upon receipt ofthis signal, the microprocessor 202 causes the power from the motor 51to be removed from the head crank 54.

The heads are moved to the back of the disk drive 12 by themicroprocessor 202. In order to hold the heads 38 in a secured positionin the back of the disk drive 12 from the position illustrated in FIG.8, the head crank 54 is rotated by the operating system 46 as describedabove in response to the depression of the eject button 13. AlthoughFIG. 8, depicts the carriage assembly 32 disposed in a particularlocation along the groove 67, the carriage assembly 32 and the heads 38can be moved to a retracted position from any position along the groove67 and the starting point of FIG. 8 is used for exemplary purposes. Asthe head crank 54 rotates counter clockwise as viewed in FIGS. 8-10, thewire 68 acts as a cam. In particular, the hook shaped end 88 of the wire68 rotates along the periphery of the head crank 54, and the profiledshaped end 90 of the wire 68 causes the drive link 70 to rotate in aclockwise direction against the pressure of the head spring 74. Whilebeing rotated, the head crank 54 is exerting a torque on the drive link70 that is greater than the torque exerted by the head spring 54.Rotation of the drive link 70 causes the trolley 78 to translate forwardand to rotate in the counter clockwise direction. As the drive link 70and the trolley 78 rotate, they move into a more acute angularrelationship with each other. The position of the head crank 54, thewire 68, the drive link 70 and the trolley 78 as the head crank 54begins to rotate is shown in FIG. 8.

Each of these components will continue to move in the directionsindicated above, until the drive link 70 is about perpendicular to theaxis of the groove, as is shown in FIGS. 9 and 10. In this position, thetrolley 78 and the drive link 70 are in their most acute angularrelationship, and the head spring 74 has been extended and is exerting atorque on the drive link 70 and the trolley 78 against the torqueexerted by the head crank 54. In addition, the protrusion 86 extendingfrom the drive link 70 engages the contacts 84. Upon engaging thecontacts 84, an electrical signal is sent to the microprocessor 202,which then removes power from the head crank 54.

When power has been removed from the head crank 54, it no longer exertsa torque on the drive link 70 and the trolley 78. Consequently, thetorque exerted by the head spring 74 causes the drive link 70 to rotatein a counter clockwise direction. As the drive link 70 rotates, theattached trolley 78 moves rotates in a clockwise direction and movesinto a more obtuse angular relationship with the drive link 70. This isshown in FIGS. 6 and 7. As the trolley 78 translates, it moves to therear of the groove 67. Since power to the head crank 54 has beenremoved, the rotation of the drive link 70 also causes the head crank 54to rotate in the clockwise direction as the wire 68 attached to thedrive link 70 rotates.

As mentioned above, the heads 38 and the carriage assembly 32 can bemoved to the retracted position by the microprocessor 202 and held in asecured position by operation of the head crank 54 and the head spring74 from any position along the groove 67. In an alternative embodiment,the head retraction system 42, does not employ a contact that isengageable with the drive link 70. This embodiment operates similarly tothe preferred embodiment described above. However, when the drive link70 has been rotated to a position that is about perpendicular to theaxis of the groove 67, there are no contacts for the drive link 70 toengage and remove power from the head crank 54 in this embodiment.Rather, the head crank 54 is driven to a stall where it can no longerrotate because the trolley 78 attached to the drive link 70 has beentranslated to the forward most position of the groove 67. Since in thisposition the trolley 78 can not translate forward and it is mechanicallylinked to the head crank 54, the head crank 54 cannot rotate anyfurther. In this stalled position, the microprocessor 202 through eithera timer or a sensor or the like will sense the head crank 54 being in astalled position and remove power to the head crank 54. As with thepreferred embodiment described above, when the power is removed from thehead crank 54, the drive link 70 and the trolley 78 will move inresponse to the torque exerted by the head spring 74. As thesecomponents move, they again move to the back of the retainer and holdthe carriage assembly 32 in the retracted position.

FIG. 11 is a graph depicting the force provided by the trolley 78 andthe head retraction system 42 to move the heads to a retracted positionas a function of its position along the retainer groove 67 and the forceneeded to move the heads to a retracted position as a function of theirposition from the rear of the retainer groove 67. As can be seen, theforce provided by the retainer system 42 is always greater than theforce needed to move the heads 38 to a retracted position. The forceprovided by the head retraction system 42 is mainly a function of theforce exerted by the head spring 74 on the trolley 78. The force neededto move the heads does not vary much with position with the exception ofthe force needed to unload the heads 38 from the disk cartridge. Inparticular, at the 26 mm. position the heads are in a disk cartridge. Asthe heads are unloaded from the disk cartridge, the frictional forcebetween the heads 38 and the cartridge is at a maximum at about the 25mm. position and therefore, the force needed to retract the heads 38 isthe highest at this point. After the heads 38 have been unloaded, theforce needed to retract them quickly drops off and is mainly a functionof the frictional force between the carriage assembly 32 and theretainer groove 67.

In summary, an improved head retract system 42 for retracting the heads38 of a disk drive 12 includes a head crank 54, a drive link 70, atrolley 78, a head spring 74 and a carriage assembly 32. Thesecomponents operate in conjunction to drive the heads 38 mounted to thecarriage assembly 32 to the rear of the disk drive 12 upon removing adisk cartridge 10 from the disk drive 12.

An Improved Ejecting System for Ejecting a Disk Cartridge from a DiskDrive

Illustrated in FIGS. 12-20 is a preferred embodiment of an eject system44 of this invention. According to this preferred embodiment, animproved eject system 44 includes an eject lever 302, an eject crank 56,an eject spring 303, a drag link 304 and a drag spring 305. This systemoperates in conjunction with the motor 51 and the gear train 52 of theoperating system 46 to eject a disk cartridge 10 from a disk drive 12.

The eject crank 56 illustrated in FIGS. 19 and 20 has an eject finger 55for interacted with the drag link 304 described below. The function ofthe eject crank 56 is to rotate in response to the operating system 56and interact with other components of the eject system 44 to eject adisk cartridge 10 from the disk drive 12. The eject crank 56 alsoincludes an eject gear 57 mounted about a central axis and a cylindricalmember 59 mounted about the same axis.

As illustrated in FIGS. 12, 13 and 16-18, the eject lever 302 in apreferred embodiment of this invention may be an integral piece. In apreferred embodiment, the eject lever 302 is rotatably mounted to thebottom of the chassis 14. The eject lever 302 may have an arm 301 forengaging a disk cartridge 10 upon insertion of and removal of the diskcartridge 10. In this embodiment, the eject lever 302 may also have anupper and a lower portion. The upper portion extends through an aperture318 in the chassis 14. FIG. 13 displays the upper portion of the ejectlever 302 extending through the aperture 318. In comparison, the lowerportion 316 remains below the aperture 318. After insertion through theaperture 318, the eject lever 302 rests in the chassis 14 as illustratedin FIGS. 1, 3, 6, 14 and 15.

In this embodiment, the eject lever 302 has a first sealing flange 306and a second sealing flange 308. The first sealing flange 306 ispreferably disposed on the upper portion, while the second sealingflange 308 is preferably disposed on the lower portion. As is explainedin further detail below, the first and the second sealing flanges 306,308 operate in conjunction with the chassis 14 of the disk drive 12 toseal the top of the disk drive 12 from the bottom of the disk drive 12.

As is illustrated in FIGS. 13 and 16-18, the lower portion of the ejectlever 302 also includes a tab 320 and a slot 322. The tab 320 and theslot 322 operate in conjunction with the drag link 304 to eject a diskcartridge 10 from a disk drive 12.

As pictured in FIGS. 3 and 6, the eject spring 303 is preferablyconnected at one end to the chassis 14 and at its other end to an ejectfinger 312 disposed on the periphery of the eject lever 302. The ejectspring 303 biases the eject lever 302 to rotate in a counter clockwisedirection as viewed in FIGS. 14-18.

The drag link 304 is preferably slidably mounted on the chassis 14, asis shown in FIGS. 3 and 6. In a preferred embodiment, the drag link 304has a plurality of channels 325 that slide in the motor stops 326mounted on the bottom of the chassis. These motor stops 326 arepreferably rigidly mounted to the chassis 14. When the drag link 304 isactuated, it slides axially along the chassis 14. More particularly, thechannels 325 slide along the motor stops 326 as the drag link 304translates.

Attached to the drag link 304 is a drag spring 305, as is depicted inFIGS. 3 and 6. The drag spring 305 is also attached to the chassis 14 tospring bias the drag link 304 to translate toward the front of the diskdrive. When activated by the drag spring 305, the drag link 304 slidesalong the motor stops 326.

Extending from the drag link 304 is an arm 307. In a preferredembodiment, the arm 307 is approximately perpendicular to the main bodyof the drag link. The arm 307 is engageable and disengageable with theeject crank 56. In particular, the finger 55 of the eject crank 56rotates in response to the operating system 46 described above. Whenrotated in a counter clockwise direction as viewed in FIGS. 3 and 6,this finger 55 can engage the arm 307 to drive the arm 307 towards theback of the disk drive 12. Because the drag link 304 is connected to thearm 307, the entire drag link 304 will translate toward the back of thedisk drive 12 when driven by the finger 55 of the eject crank 54.

As mentioned above, the eject lever 302 has a slot 320 and a tab 322disposed on its lower portion. This slot 320 and tab 322 are adaptableto mate with the drag link 304. More particularly, the drag link 304 hasa tongue 324 that is engageable with the slot 320 and tab 322, as isbest seen in FIGS. 16-18. When the eject lever 302 is in its springbiased position as depicted in FIG. 16, (with a disk cartridge removedfrom the disk drive) the tongue 324 of the drag link 304 rests againstthe tab 322. The drag spring 305 is biasing the drag link 304 totranslate toward the front of the disk drive 12, but because the tongue324 is resting against the tab 322, the drag link 304 cannot translate.Thus, with a disk cartridge 12 removed, the drag link 304 is held in theback of the disk drive 12 by the eject lever 302 against the pressure ofthe drag spring 305.

Upon inserting a disk cartridge 10 into the disk drive 12, as shown inFIG. 16, the disk cartridge 10 engages the eject lever 302. When engagedwith the eject lever 302, the disk cartridge 10 rotates the eject lever302 in a clockwise direction about its axis, as illustrated in FIG. 17.(FIGS. 16-18 depict only a portion of a disk cartridge 10 in order toenhance the description of the eject system 44). As the eject lever 302is rotated, it rotates against the pressure of the eject spring 303.Eventually, the tongue 324 of the drag link 304 no longer rests againstthe tab 322, and it becomes aligned with the slot 320 of the eject lever302, as depicted in FIG. 17. When aligned, the drag link 304 translatestoward the front of the disk drive 12 due to the tension exerted by thedrag spring 305. As the drag link 304 translates, the tongue 324 isinserted into the slot 320, as shown in FIG. 18. Further movement of thedrag link 304 is prevented when the tongue 324 is fully inserted intothe slot 320. Additionally, the eject lever 302 is prevented fromrotating further in the clockwise direction because of the engagement ofthe slot 320 and the tongue 324. Thus, with a disk cartridge 10 loadedinto the drive 12, as depicted in FIGS. 14 and 18, the drag link 304 hastranslated towards the front of the drive 12 and the eject lever 302 hasbeen rotated against spring pressure. In its rotated position shown inFIGS. 3 and 6, the drag link 304 holds the eject lever 302 against thetorque exerted by the eject spring 303.

After a disk cartridge 10 has been inserted into the disk drive 12, therelative positions of the eject lever 302, the drag link 304 and theeject crank 56 are illustrated in FIGS. 3 and 18. In order to eject aloaded disk cartridge 12 from the disk drive 10, an eject button 13disposed on the disk drive 12 is depressed. Activation of the ejectbutton 13 will cause as is discussed in detail below, the microprocessorto power the operating system 46. When the operating system 46 ispowered as described above, it causes the eject crank 56 to rotate in acounter clockwise direction as viewed in FIG. 3. Upon rotating, thefinger 55 of the eject crank 54 contacts the arm 307 of the drag link304 and pushes the arm 307 as it rotates against the pressure of thedrag spring 305. As the eject finger 55 rotates and the arm 307 ispushed, the drag link 304 moves towards the back of the disk drive 12.When the drag link 304 translates, the tongue 324 of the drag link 304disengages from the slot 320 of the eject lever 302. Upon disengagementfrom the drag link 304, the eject lever 302 is free to rotate, and theeject spring 303 biases the eject lever 302 to rotate in a counterclockwise direction, as viewed in FIGS. 16 and 18. When the eject lever302 rotates, it ejects a disk cartridge 10 from the disk drive 12, asdepicted in FIGS. 15 and 16. After the eject lever 302 rotates, the tab322 of the eject lever 302 contacts the tongue 324 of the drag link 304to hold the drag link 304 in its spring loaded position.

It is important to keep dusk, dirt and other contaminants from beingtransported from the top of the chassis 14 to the bottom of the chassis14. Potentially, this can occur through openings in the chassis such asthe aperture 318. In order to prevent this, the eject lever 302 has thetwo sealing flanges 306, 308 as described above. As can be seen in FIG.15, when the eject lever 302 is in the unloaded position, that is when adisk cartridge 10 has not been loaded into a disk drive 12, the firstsealing flange 306 covers the majority of the aperture 318. Thisprevents any dusk or contaminants from being transported through theaperture 318.

When the eject lever 302 has been rotated to the loaded position, thatis when the disk cartridge 10 is fully inserted into the disk drive 12,the first sealing flange 306 rotates clockwise and no longer covers themajority of the aperture 318. However, as the eject lever 302 rotates,the second sealing flange 308 prevents dusk or contaminants fromtraveling through the aperture 318 as it covers the bottom of theaperture 318 shown in FIG. 14.

One advantage, although certainly not the only advantage of the ejectlever 302 of this invention is that it allows the transfer of arelatively large torque from the top surface of the chassis 14 to thebottom of the chassis for instance, the eject lever 302 is a singleintegral piece and it transfers the torque generated by its rotation tothe drag link 304. Having one integral piece to transfer the torque fromabove the chassis 14 to below the chassis 14 is advantageous because asingle piece can efficiently transfer a relatively high torque betweensurfaces of the chassis. Moreover, a single integral may be simpler toassemble than a multiple piece apparatus. Although in a preferredembodiment the eject lever 302 is a single integral piece, it mayinclude multiple pieces which are disposed above and below the chassis14.

As shown in FIGS. 2, 3, 6 and 16-18 the ejecting system 42 may employ acartridge retainer 150 that has a projection 152 extending from an endof the retainer 150. The cartridge retainer 150 is pivotally mounted atan axial end 154 and free at the other axial end having the projection152. The cartridge retainer 150 is preferably flexible so that it canpivot up and down about its axial end 154. As the cartridge retainer 150pivots, the projection 152 can be inserted through an aperture 156 inthe chassis 14. As depicted in FIG. 5, the cartridge 10 may have a hole158 into which the projection 152 can be inserted. When inserted intothe hole 158, the projection 152 holds the disk cartridge 10 in the diskdrive 12.

The drag spring 305 is connected to the cartridge retainer 150, and itspring biases the cartridge retainer 150 to a position where theprojection 152 does not extend through the aperture 156. The cartridgeretainer also has two channel surfaces 162 that extend perpendicularfrom the retainer 152 to form a channel. These channel surfaces 162interact with a riding surface 160 extending from the drag link 304.This riding surface 160 is preferably ramped as seen in FIGS. 16 and 17.When the drag link 304 translates as described above, it rides inbetween the channel surfaces 162 to push the cartridge retainer towardsthe chassis 14 and cause the projection 152 to extend through theaperture 156 and into the hole in the cartridge to hold a loaded acartridge fly in place.

In particular, before a cartridge is inserted the cartridge retainer 150is in the position shown in FIGS. 2 and 16. In this position theprojection 152 does not extend through the aperture 156. As the draglink 304 translates as described above, the riding surface 160 ridesbetween the channel surfaces 162 and due to its ramped surface pushesthe cartridge retainer 150 towards the chassis 14. As it pushes on thecartridge retainer 150, the projection is inserted though the aperture156 and into the hole in the disk cartridge 10. This position isillustrated in FIGS. 3 (with the drag spring 305 removed) and 17.

When a disk cartridge is to be ejected, the drag link 304 is operated asdescribed above. As the drag link 304 translates to the rear of the diskdrive 12, the riding surface 160 exits the channel formed by the channelsurfaces 162. With the riding surface 160 out of this channel, dragspring 305 pulls the cartridge retainer 150 and the projection 152 outof the hole of the disk cartridge and the aperture in the chassis 14 tothe position shown in FIGS. 2 and 16.

Motor Loading System for a Disk Drive

The disk drive 12 of this invention may also have a motor loading system45 that includes an inner motor ring 401 disposed on a disk drive motor400 and an outer motor ring 404 disposed on the chassis 14. The primaryfunction of these rings are to engage the disk drive motor 400 with adisk cartridge 10 when loaded into the disk drive 12, and to disengagethe disk drive motor 400 from a disk cartridge 10 so that the cartridge10 can be ejected from the disk drive 12.

This disk drive motor 400 may be a spindle motor that interacts with thehub 16 of a disk cartridge depicted in FIG. 5. This motor 400 may becircular in shape, as shown in FIG. 1 to facilitate engagement with thehub 16. The disk drive motor 400 is preferably mounted on a rotatableshaft 409. In a preferred embodiment, the disk drive motor 400 isattached to the shaft 409 with an interference fit, but other knownmethods of attachment may be used. A bushing 420 may be placed on theshaft above the motor 400 for engaging the hub 16 of a disk cartridge10. Washers 422 may be disposed on the shaft above and below the motor400 to retain the motor 400 on the shaft 409. These washers 422 may alsobe attached to the shaft 409 with an interference fit. A cover plate 424may be affixed to the lower portion of the disk drive motor 400, asshown in FIG. 2, 6 and 36-39.

In a preferred embodiment, the disk drive motor 400 has an inner motorring 401 with threads 402 running around the circumference. This innermotor ring 401 is preferably constructed from plastic or anothersuitable material. The inner motor ring 401 may be connected to thecover plate 424 with heat stakes 426 as shown in FIGS. 2, 6 and 36-39.Alternatively, fasteners, adhesives or a variety of other fasteningtechniques may be employed.

The threads 402 of the inner motor ring 401 are adaptable to mate with athreaded outer motor ring 404 disposed in a cavity 406 in the chassis14. The outer motor ring 404 is also preferably constructed from plasticor another suitable material.

The outer motor ring 404 may have a plurality of detents 408 extendingradially from an outer surface. These detents 408 can be mated with aninterference fit to a plurality of indentations 410 in the chassis 14.Other known methods of fastening may be employed.

Extending from the inner motor ring 401 may be a slotted member 412. Inthe preferred embodiment shown in FIGS. 2, 3 and 34-39, the slottedmember 412 extends approximately parallel to the chassis 14. The slotmember 412 functions to interact with a drag link post 414 extendingfrom the drag link 304 to load and unload the disk drive motor 400. Theslotted member 412 may be molded to the inner motor ring 401 or attachedwith other known fastening methods.

Affixed to the outer motor ring 404 is a motor snap 416. In thepreferred embodiment shown in FIGS. 2, 3, 6 and 34-39, the motor snap416 is a cantilever beam that functions as a spring when inserting thedisk drive motor 400. When a disk drive motor 400 is inserted, the motorsnap 416 functions to prevent rotation of the disk drive motor clockwiseas viewed in FIGS. 2, 3, and 34-39. This prevents the disk drive motor400 form becoming disconnected from the chassis 14 in the event the diskdrive motor 400 is forced to rotate in the clockwise direction. Becausethe motor snap 416 prevents the disk drive motor 400 from becomingdislodged from the chassis 14, it permits the disk drive motor 400 toremain assembled to the chassis 11 as it moves between an unloaded and aloaded position. Without the motor snap 416, either a more complexattachment mechanism requiring a relatively more complex assemblingprocess would be required or the disk drive motor 400 would not have ameans for preventing it from becoming dislodged.

FIGS. 34-39 depict the motor assembling sequence. By way of overview,during the assembling sequence the disk drive motor 400 is inserted intoand connected to the disk drive 12 where it rests in an unloadedposition. In the unloaded position, the disk drive motor 400 is notcoupled to a disk cartridge 10. When a disk cartridge 10 is insertedinto the disk drive 12, the disk drive motor 400 can then be moved toits loaded position. In the loaded position, the disk drive motor 400engages the disk cartridge 10 to rotate its storage medium. When thedisk cartridge 10 is ejected from the disk drive 12, the disk drivemotor 400 is moved back to its unloaded position.

FIG. 36 illustrates the disk drive motor 400 being inserted into thedisk drive 12. As the disk drive motor 400 is inserted, the threads ofthe inner motor ring 401 are engaged to the threads disposed on theouter motor ring 404, as shown in FIG. 37. Additionally, the slottedmember 412 is fit over the drag link post 414 and over the motor snap416. Upon engaging the motor snap 416, the slotted member 412 deflectsthe motor snap 416 towards the chassis 14.

As shown in FIG. 38, the disk drive motor 400 is then rotated counterclockwise to mate the threads of the inner motor ring 401 with thethreads of the outer motor ring 404. As the rings are mated, the diskdrive motor 400 moves towards the top of the disk drive 12. Duringrotation of the disk drive motor 400, the slotted member 412 pulls thedrag link 304 because of its engagement with the drag link post 414. Themotor snap 416 becomes uncovered by the slotted member 412 as the diskdrive motor 400 is rotated, as shown in FIG. 38. When uncovered, themotor snap 416 springs from its deflected position to its undeflectedposition. In its undeflected position, the motor snap 416 rests near theslotted member 412. Since the motor snap 416 is affixed to the outermotor ring 401, it cannot rotate. Thus, the slotted member 412 cannotrotate in the counter clockwise direction past the motor snap 416 asviewed in FIGS. 36-39 because it will engage the fixed motor snap 416.Furthermore, since the inner motor ring 401 is attached to the slottedmember 412 it cannot rotate in this direction either.

After insertion, the disk drive motor 400 is not in a position to engagea loaded disk cartridge. This position is referred to as the unloadedposition. The unloaded position of the inner motor ring 401, the outermotor ring 404, the slotted member 412 and the motor snap 416 aredepicted in FIG. 34. The threads of the disk drive motor 400 can berotated further in the clockwise direction as viewed in FIG. 34 to movethe disk drive motor 400 to a loaded position where it can engage aloaded disk cartridge.

The disk drive motor 400 can be moved from the unloaded position to theloaded position as follows. As discussed in detail above, when a diskcartridge 10 is inserted into a disk drive 12, the drag link 304translates towards the front of the disk drive 12 in response torotation of the eject lever 302. As the drag link 304 translates, thedrag link post 414 pushes the slotted member 412 and drive the innermotor ring 401 to rotate in a clockwise direction, as depicted in FIGS.39 and a counter clockwise direction as viewed in FIGS. 34 and 35. Uponrotating with the inner motor ring 401, the disk drive motor 400 isdriven towards the top of the disk drive 12 into its loaded positionwhere it enters the opening 21 of the disk cartridge 10 and engages thehub 16 of the disk cartridge 10. In this position the disk drive motor400 can rotate the hub 16 to operate the disk cartridge 10 for storageand retrieval of information.

In order to unload the disk drive motor 400, the operating system 46described above operates in conjunction with the eject system 44 totranslate the drag link 304. As the drag link 304 translates, the draglink post 414 interfaces with the slotted member 412 to drive the diskdrive motor 400 to rotate about the outer ring 404 in a clockwisedirection as viewed in FIG. 39. As the disk drive motor 400 rotates itmoves to the unloaded position, shown in FIGS. 34 and 38 and disengagesfrom the opening 21 and the hub 16 of the disk cartridge 10.

If the disk drive 12 is subject to a dynamic force, such as mechanicalshock, the disk drive motor 400 has the potential to rotate and becomedislodged from the chassis 14. This could happen if the disk drive motor400 rotates past the point where the threads of the inner motor ring aremated with the threads of the outer motor ring. In order to preventthis, the motor snap 416 prevents the disk drive motor 400 from rotatingto the point where it becomes dislodged from the chassis 14. The motorsnap 416 also facilitates loading the disk drive motor 400 because it isflexible. It is preferably flexible because it interferes with theinsertion of the disk drive motor 400. The motor snap 416 interfereswith the insertion of the disk drive motor 400 because it must belocated at a certain point along the outer motor ring to preventrotation of the motor 400 past this certain point. Additionally, theslotted member 412 must be disposed along the inner motor ring at acertain point so that it can interface with the drive link post 414.Because of the required location of these components, the motor snap 416interferes with the slotted member 412 upon inserting the disk drivemotor 400 into the chassis 14. In order to facilitate the insertion ofthe disk drive motor 400, the motor snap 416 is flexible so that it candeflect upon insertion of the disk drive motor 400. After the disk drivemotor 400 has been inserted and has been rotated, the motor snap 416 canthen deflect back to its original position and prevent rotation of thedisk drive motor 400 past a certain point where it would becomedislodged from the chassis 14.

Because the motor snap 416 may be integral with the outer motor ring, itcan be manufactured relatively easily through a molding or similarprocess. Additionally, a motor snap 416 that is integral with the outermotor ring facilitates insertion of the disk drive motor 400.

The preferred embodiments described herein are illustrative only and,although the examples given include many specificities, they areintended as illustrative of only one possible embodiment of theinvention. Other embodiments and modifications will, no doubt, occur tothose skilled in the art. Thus, the examples given should only beinterpreted as illustrations of some of the preferred embodiments of theinvention, and the full scope of the invention should be determined bythe appended claims and their legal equivalents.

What is claimed is:
 1. A computer comprising: a disk drive that isadaptable to hold a head assembly having heads for interfacing with adisk cartridge in a retracted position; the disk drive comprising: (i) amoveable trolley disposed in the disk drive that is adaptable to bemoved between a spring loaded position that permits movement of the headassembly and an unloaded position that prevents movement of the headassembly from the retracted position; (ii) a motor disposed within thedisk drive and coupled to the trolley that is adaptable to move thetrolley to the spring loaded position; (iii) a spring disposed withinthe disk drive and coupled to the trolley that spring biases the trolleyto the retracted position; (iv) a retainer disposed with the disk drivethat has a groove in which the trolley moves between the spring loadedand unloaded positions; and a microprocessor that powers the motor tomove the trolley to the spring loaded position.
 2. The computer of claim1, further comprising a head crank that couples the motor to thelinkage.
 3. The computer of claim 1, further comprising an eject buttondisposed on a periphery of the disk drive and linked to themicroprocessor, the eject button being adaptable to be depressed andcommunicate a signal to the microprocessor to remove power from themotor and thereby move the linkage to the unloaded position.
 4. A diskdrive, comprising: a linkage having an axial end; a rotatable crankdisposed within the disk drive; a connecting mechanism for connectingthe linkage to the crank comprising a recess disposed in an upperperipheral surface of the crank that is adaptable to receive the axialend of the linkage, and a top surface of the crank which covers therecess and prevents the axial end of the linkage from becomingdisengaged from the recess when the crank is rotated.
 5. The disk driveof claim 4, wherein the rotatable crank comprises a head crank that isadaptable to be rotated to move a trolley disposed within the disk driveto a retracted position in which it prevents movement of a head assemblydisposed within the disk drive.
 6. A disk drive that has a system thatis adaptable to hold a head assembly having heads for interfacing with adisk cartridge in a retracted position; the disk drive comprising: (i) amoveable trolley disposed in the disk drive that is adaptable to bemoved between a spring loaded position that permits movement of the headassembly and an unloaded position that prevents movement of the headassembly from the retracted position; (ii) a motor disposed within thedisk drive and coupled to the trolley that is adaptable to move thetrolley to the spring loaded position; (iii) a spring disposed withinthe disk drive and coupled to the trolley that spring biases the trolleyto the retracted position; and (iv) a retainer disposed with the diskdrive that has a groove in which the trolley moves between the springloaded and unloaded positions.
 7. The disk drive of claim 6, furthercomprising a head crank that couples the motor to the linkage.